Sudden cardiac death is a natural death due to cardiac causes. In some cases, sudden cardiac death is caused by ventricular fibrillation and/or ventricular tachycardia. Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly. Ventricular fibrillation is a commonly identified arrhythmia in cardiac arrest patients that is often only detectable by electrocardiography. Ventricular tachycardia is a tachycardia, or fast heart rhythm, that originates in one of the ventricles of the heart.
An implantable cardioverter-defibrillator (ICD) is a small battery-powered electrical impulse generator that is implanted in patients who are at risk of sudden cardiac death due to ventricular fibrillation and/or ventricular tachycardia. An ICD is programmed to detect cardiac arrhythmia and correct it by delivering a jolt of electricity. Implanting an ICD is similar to implanting a pacemaker. Similar to pacemakers, ICDs typically include electrode wire(s) that pass through a vein to the right chambers of the heart, usually lodging in the apex of the right ventricle.
While ICD insertion is a safe and routine procedure, as with any surgical procedure, there is a risk for complications. The range of complications for ICDs is extensive as problems can frequently emerge with the electrode wires. Further, ICDs may be relatively expensive. There are currently no reliable predictors of sudden cardiac death to identify the best candidates for ICD implantation.
Thus, there remains a need for improved systems for assessing a risk of sudden cardiac death.